1. Field of the Invention
The present invention relates to an improvement of a floating magnetic head used in a rigid magnetic disk unit used for a computer and the like.
2. Description of the Related Art
It is a general tendency that a track width of a floating magnetic head used for a rigid magnetic disk unit is getting narrower in order to achieve high density recording, and therefore, a laminated core having a narrow track width by forming magnetic thin films composed of Fe-Al-Si alloy and amorphous magnetic material on a non-magnetic slider have been proposed. Examples of such floating magnetic head are shown in FIG. 3 (Japanese Patent Laid-Open No. 3-19119), FIG. 4 (Japanese Patent Laid-Open No. 3-272004), FIG. 5 (Japanese Patent Laid-Open No. 3-49019), and FIG. 6 (Japanese Patent Laid-Open No. 3-125320).
A floating magnetic head 1 shown in FIG. 3 has a nearly rectangular slider 2 made of a non-magnetic material. Magnetic films 5 made of Fe-Al-Si alloy which is a part of magnetic head cores 4 are sandwiched in rails (floating surface) 3 provided on the slider 2. C-shaped magnetic head cores 7 having magnetic films 6 made of Fe-Al-Si alloy which form the main core portion 4 together with the magnetic films 5 are bonded to the slider 2. The magnetic head cores 7 are structured so that the head core side magnetic films 6 are sandwiched by non-magnetic substrates 8 and that the head core side magnetic films 6 are connected to the magnetic films 5 magnetically through a gap.
The reference numeral 9 in the figure indicates gaps.
In a floating magnetic head 1 shown in FIG. 4, a magnetic film 5 is formed in the middle part of a slider 2.
In a floating magnetic head 1 shown in FIG. 5, laminated magnetic films 5 are sandwiched in one of rails 3 of a slider 2 and a magnetic head core 7 is bonded to one end of the slider 2. The magnetic head core 7 comprises laminated magnetic films 6. The head core side magnetic films 6 are connected magnetically to the magnetic films 5 to form a gap 9.
In a floating magnetic head 1 shown in FIG. 6, a longitudinal main core portion 4 in which a magnetic film 6 is sandwiched by substrates 8 made of a non-magnetic material is inserted to and bonded with a slit 10 formed on a slider 2.
In the floating magnetic heads 1 shown in FIGS. 3, 4, 5 and 6, however, there has been a problem that they are susceptible to an external magnetic field, thereby reducing their S/N ratio, because the main core portion 4 which is obtained by forming and laminating magnetic films (the magnetic films 5 and 6) is formed across the whole length of the rail (floating surface) 3. Further, there has been another problem that because abrasion resistance of the magnetic films (the slider side magnetic film 5 and head core side magnetic films 6) and of the non-magnetic slider 2 are different, partial abrasion is generated between the magnetic films and the slider 2, thereby damaging their reliability due to a deterioration of CSS resistance caused by steps produced between them and dust adhered thereon. Materials which have better CSS resistance could be chosen for the slider 2, but they were sometimes inferior in terms of the compatibility with the magnetic films.
In the floating magnetic head 1 shown respectively in FIGS. 3, 4 and 5, because the bonding strength is maintained only by a fillet glass, they tend to lack the bonding strength.
In the floating magnetic head 1 shown in FIGS. 3, 4 and 5, the laminated core (the main core portion 4) cannot but be thinned down so much if a track is to be narrowed down, causing a problem that magnetic reluctance on the rear gap 11 is increased compared to the front gap 9, and thereby the write and readback efficiency is degraded.
Still more, the floating magnetic head 1 shown respectively in FIGS. 3, 4, 5 and 6 had a difficulty in aligning tracks at the gap 9, thereby an effective track width would be different from its desired size.
Accordingly, it is an object of the invention to overcome the aforementioned problems by providing a floating magnetic head which allows to improve the CSS characteristic, to assure a fully large bonding strength and to improve the write and readback efficiency by assuring an adequate magnetic reluctance.